Cholesterol feeding to rats does not modulate the expression of binding sites for HDL on liver membranes.

The binding of HDL, Apo-E-free, was studied in rats fed a cholesterol rich diet for 2, 4 and 7 days. Plasma cholesterol increased up to 16-fold (from 55 to 900 mg/dl); liver cholesterol was also raised, from 0.5 to 16 mg/g of tissue. The HDL binding to membrane preparations was not affected while the binding of beta VLDL was reduced to about 50% of the controls. These data show, therefore, that liver binding sites for HDL are refractory to regulation by dietary cholesterol.